Schiff base derivatives of amino acids will be used as starting materials for the preparation of various amino acid analogs as well as for peptide synthesis. The alpha-alkyl amino acids will be prepared using our recently developed method for the synthesis of amino acid derivatives by phase-transfer reactions. The racemic products obtained will be resolved to yield both D- and L-enantiomers. The N-alkyl amino acids will be synthesized by either a modified phase-transfer procedure (for the alpha-substituted cyclic alpha-amino carboxylic acids) or by alkylation of the Schiff base of the corresponding amino acid ester (for the N-methyl amino acids). The use of Schiff bases for primary amino protection in peptide synthesis will also be explored. Because of the structural similarity between the Schiff base synthons and the benzodiazepines, these derivatives will be screened for biological activity.